OBJECTIVES: 1. Document the clinical characteristics and clinical course of congenital cataracts in the miniature schnauzer dog using slit-lamp biomicroscopy. 2. Confirm its mode of inheritance as simple autosomal trait with appropriate breedings. 3. Study the embryogenesis of gestation and evaluation of tissues with light microscopy. 4. Study the progression of the cataract and associated ocular pathology correlating clinical findings (#1 above) with histopathology at various stages of the disease in the developing puppy. 5. Define patterns of protein kinetics in the normal and cataractous lens at various stages of cataract development (including fetal) using radioisotope techniques. 6. Quantitative and qualitative characterization of lens proteins and glutathione in the normal canine lens and in various stages of cataract development. 7. Establish a potential spontaneous biomedical model for cataractogenesis in man.